1. Field of the Invention
The present invention relates to a method of production of a multilayer circuit board comprised of a multilayer structure circuit formed by a plurality of interconnect layers and insulation layers stacked together and a semiconductor chip included therein.
2. Description of the Related Art
Multilayer circuit boards with built-in semiconductor chips are being widely used as thin boards. The built-in semiconductor chips have to be made as thin as possible in order for them to fit in the limited board thickness. As means for this, the practice has been to polish the back surfaces so as to reduce the thickness of the semiconductor chips (for example, see US 2001/0008794A1, [00103] to [0110]). Such a semiconductor chip polished on its back surface, however, creates the following problem in the process of production of a multilayer circuit board.
That is, when placing the semiconductor chip to be built in, with its active surface facing down, on a lower interconnect layer and then forming an insulating film over it, sometimes the smoothly polished back surface will have insufficient bondability with the insulating film laid over it. As a result, when performing reflow as part of the process of production of the multilayer circuit board or running an environment test as a test of the finished multilayer circuit board, the problem has arisen of the insulating film ending up being peeled off from the semiconductor chip due to the shrinkage stress of the resin.